Exemplary embodiments relate to a method of programming a nonvolatile memory device.
Recently, there has been an increasing demand for nonvolatile memory devices which can be electrically programmed and erased and which do not require the refresh function of rewriting data at specific intervals.
Particularly, there is an increasing demand for nonvolatile memory devices which can be electrically programmed and erased and can retain its data even without the supply of power. To develop high-capacity memory devices capable of storing a large amount of data, a technique for the high integration memory cells is being developed. A typical nonvolatile memory device includes a number of strings each having a number of memory cells coupled to each other in series. Each memory cell array includes a number of the strings.
Each of the strings of the nonvolatile memory device has a structure in which a number of the memory cells are coupled to each other in series between a bit line and a source line. By having such a string structure, the number of contacts of the bit line and the source line and the size of each memory cell can be reduced, thus enabling a high-capacity memory device. However, there is a disadvantage in that with a reduction in the size of the memory cell, the cell current of the memory cell is significantly reduced and so the access speed is also reduced.
For this reason, the nonvolatile memory device compromise for such a speed decrease by storing and reading data in such a way as to program and read data at the same time on a page basis.
To provide a faster data I/O speed, different techniques for reducing the program or read time have been attempted.